23,24-secoalkaloids



United States Patent US. Cl. 260-287 7 Claims ABSTRACT OF THE DISCLOSURE Brucine, vomicine and alkaloids related thereto are subjected to reduction conditions yielding correspondingly reduced 23,24-secoalkaloids which are useful as tranquilizers and anti-depressants.

This invention relates to and has for its objects the provision of new physiologically active compounds, novel processes for their production and new intermediates useful in the preparation thereof.

More particularly, this invention relates to alkaloid compounds selected from the group consisting of those having the formulas (I) and (I and the quaternary salts thereof, wherein the 21,22-position is saturated or double-bonded; (i) represents the cis or trans position to the G12 hydrogen; X is hydroxy or methoxy; R is hydrogen or hydroxy; R is hydrogen or acyl; and n is an integer from 1 to 2, with the proviso that R is acyl only when R is hydrogen.

Among the suitable acyls may be mentioned the acyl radicals of a hydrocarbon carboxylic acid of less than 12 carbon atoms, as exemplified by the lower alkanoic acids (e.g., acetic, propionic, butyric, hexanoic, decanoic and enanthic acid), the lower alkenoic acids (e.g., acrylic acid), the cycloalkane carboxylic acids (e.g., cyclobutane carboxylic acid), the monocyclic aromatic carboxylic acids (e.g., benzoic), and the monocyclic aryl lower alkanoic acids (e. g., phenacetic and B-phenyl propionic acid).

The final products of this invention are physiologically active substances which surprisingly possess both antidepressant and tranquillizing activity at doses showing no convulsant activity. Hence, the compounds of this invention may be used in lieu of chlordiazepoxide or imipramine.

The compounds of the present invention can be prepared and administered to warm-blooded animals, in a wide variety of oral and parenteral dosage forms.

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For preparing pharmaceutical compositions from the physiologically active compounds of this invention, pharmaceutically acceptable carriers can be either solid or liquid. Solid form preparations include powders, tablets, dispersible granules, capsules, cachets and suppositories. A solid carrier can be one or more substances which may also act as diluents, flavoring agents, solubilizers, lubricants, suspending agents, binders or tabletdisintegrating agents: it can also be an encapsulating material. In powders the carrier is a finely divided solid which is in admixture with the finely divided compound. In the tablets the compound is mixed with carrier having the necessary binding properties in suitable proporations and compacted in the shape and size desired. The powders and tablets preferably contain from 5 or 10 to 99% of the active ingredient. Suitable solid carriers are magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, tragacanth, methyl cellulose, sodium carboxymethylcellulose, a low melting wax and cocoa butter. The term preparation is intended to include the formulation of the compound with encapsulating material as carrier providing a capsule in which the compound (with or without other carriers) is surrounded by carrier, which is thus in association with it. Similarly, cachets are included. Tablets, powders, cachets and capsules can be used for oral administration.

Liquid form preparations include solutions, suspensions and emulsions. As an example may be mentioned Waterpropylene glycol solutions for parenteral injection. Liquid preparations can also be formulated in solution in aqueous polyethylene glycol solutions. Aqueous suspensions suitable for oral use can be made by dispensing the finely divided compound in water with viscous material, natural or synthetic gums, resins, etc., for example, gum arabic, ion-exchange resins, methyl-cellulose, sodium carboxymethylcellulose and other Well known suspending agents.

Preferably, the pharmaceutical preparation is in unit dosage form. In such form the preparation is sub-divided in unit doses containing appropriate quantities of the compound: the unit dosage form can be a packaged preparation, the package containing discrete quantites of prepration, for example, packeted powders of vials or ampules.

The unit dosage form can be a capsule, cachet or tablet itself, or it can be the appropriate number of any of these in packaged form. The quantity of compound in a unit dose of preparation may be varied or adjusted from a 0.5 mg. to 100 mg. (generally within the range of 0.5 to 10 mg. for use as an anti-depressant agent and 10 to 50 mg. for use as a tranquillizer) according to the particular application and the potency of the active ingredient.

The claimed composition having physiological activity can be incorporated into pharmaceutical formulations including sustained-release agents.

The compound of this invention can be prepared by reducing a compound of the Formula II:

wherein X and n are as hereinbefore defined, in liquid ammonia with a lower alkanol and a metal from Group I or Group II of the Periodic Table, preferably sodium, to yield compounds of the formulae iii OH H 3 wherein X and n are as hereinbefore defined.

Higher yields of compounds of Formula III are obtained by prolonged reduction of the initial compound.

Alternatively, the final products can be prepared by similarly reducing a compound of the Formula V:

(V) wherein X and n are as hereinbefore defined, to yield compounds of the formulae:

wherein X and n are as hereinbefore defined.

A still further process for preparing the final products is to reduce in ammonia with a lower alkanol and a metal from Group I or II of the Periodic Table, a compound of the Formula VIII:

(VIII) wherein X and n as hereinbefore defined, and Z is methylene or keto C=O), to yield the compound of the Formula IX:

wherein R X and n are as hereinbefore defined.

The esters of this invention can be prepared by acylating the corresponding hydroxy compounds in the usual manner. Thus, to prepare the IZ-acyloxy derivatives wherein the acyl radical corresponds to the acyl radical of a hydrocarbon carboxylic acid of less than 12 carbon atoms, either the acyl halide or acid anhydride of a lower alkanoic acid, lower alkenoic acid, monocyclic aryl carboxylic acid, monocyclic aryl lower alkenoic acid, cycloalkane carboxylic acid or cycloalkene carboxylic acid is employed as a reactant.

The tertiary nitrogen atoms of the final products of this invention may be quaternized by any conventional method, such as by treatment with an alkyl halide in an organic solvent.

Among the suitable starting materials that are utilizable in the process of this invention which are commercially available or can be made by any conventional method, may be mentioned brucine, brucidine, u-colubrine, {3- colubrine, a-colubridine, fl-colubridine, vomicidine, vomicineand the like.

The following examples illustrate the invention (all temperatures being in centigrade):

EXAMPLE 1 IO-hydroxy-Z3,24-secobrucidine 5 gm. of sodium is added piecemeal over a 1 hour period to a vigorously stirred dispersion of 5 gm. of brucine in 500 m1. of liquid ammonia containing 5 ml. of ethanol. 10 gm. ammonium chloride is then added and the ammonia allowed to evaporate. Water is added to the residue and the precipitate is filtered off and washed with 10% aqueous sodium hydroxide. The precipitate is dissolved in benzene, percolated through a short column of alumina. The eluate is evaporated to dryness in vacuo and the residue is recrystallized from acetone-ether to give 1.5 gm. of lO-hydroxy-Z3,24-secobrucidine as a solvate having a melting point of 163l70. Distillation of an aliquot at 220/2 mm. yields the 10-hydroXy-23, 24-secobrucidine as a glass, containing about 25% of the lO-hydroxy-Z1,22-dihydro-23,24-secobrucidine.

Analysis.-Calcd. for C H N O (percent): C, 69.3; H, 7.6. Found (percent): C, 70.0; H, 7.6.

EXAMPLE 2 23,24-secobrucidine 3 gm. of sodium is added piecemeal over a 30 minute period to a vigorously stirred dispersion of 2 gm. of brucidine in 300 ml. of liquid ammonia containing 2 ml. of of methanol. After a further 10 minutes, 2 gm. of ammonium chloride is added followed by 300 ml. of water. The mixture is extracted with ether and an aliquot is dis-s 6 tilled at 190210/2 mm. to yield 23,24-secobrucidine EXAMPLE 7 as a $1353 10,16-dihydroxy-23,24-secovomicidine and 10,16-

Analysis.Calcd. for C23H30N2O3 (percent): C, 72.2; H, 7.9; N, 7.3. Found (percent): 0, 72.1; H, 8.3; N, 7.0. dlhydmxy 2122 dlhydmzszi Sewvomlcldme Following the procedure of Example 4, but substituting EXAMPLE 3 vomicine for brucidine there is obtained a mixture of 23,24-secobrucidine acetate 10,16-dihydroxy-23,24 secovomicidine and 10,16-dihydroxy-Zl,22-dihydro-23,24-secovomicidine which may be separated by chromatography on silica gel and eluting with the appropriate solvents.

0.4 gm. of 23,24-secobrucidine is placed in 3 ml. of pyridine and 2.5 ml. of acetic anhydride overnight at room temperature. The solvent is evaporated and the product is distilled at 200/ 2 mm. to yield 23,24-secobru- EXAMPLE 8 cidine acetate as a glass.

Analyris.Calcd. for C H N O (percent): C, 70.7; 16-hydroxy-23,24-secovomicidine and 16-hydroxy-2l,22- H, 7.6. Found (percent): c, 69.7; H, 7.6. dihydro-23,24-secov0mic1dine In a similar manner by substituting any other acid anhydride or acyl chloride for the acetic anhydride of Example 3, the corresponding ester is formed.

Following the procedure of Example 4, but substituting vomicidine for brucidine there is obtained a mixture of 16 hydroxy 23,24 secovomicidine and 16 hydroxy- EXAMPLE 4 21,22-dihydro-23,24-secovomicidine which may be sepa- 21,22 dihydr0 2324 Secobrucidine rated by chromatography on silica gel and eluting with the appropriate solvents. 3.5 gm. of sodium is added piecemeal over a minute period to a vigorously stirred dispersion of 4 gm. of bruci- EXAMPLE 9 dine in 400 Of liquid ammfmia containing 4 of To prepare 1000 tablets, each containing 25 mg. of methanol- After a further 45 mmutes, of ammo 25 21,22-dihydro-10-hydroxy-23,24-secobrucidine, the follownium chloride is added and the mixture is worked up as ing ingredients are used: in Example 2 to give 2 gm. of 21,22-dihydro-23,24-seco- Gm brucidine as an acetone solvate having a melting point of 21,22 dihydm 10 hydr0Xy 2324 Sec0bmcidine 250 192-196. The analytical sample, prepared by rccrystalli- Milk Sugar 164 12 zation from acetone and drying in vacuo has a melting 3O Ethylcenulose 01 P011110f 1952O2u- Corn starch 13.0 Analysis.Calcd. for C23H32N2O3 (Pm'CeIlt): C, 71-8; Sodium Benzoate 02 H, 8.4. Found (percent): C, 71.6; H, 8.4. Talc EXAMPLE 5 Acacia powder 2.5 Magnesium stearate 1.5

1OZ-hydroxy-23,24-secoco1ubridine and 212,22-dihydro- 10; hydroXy 23,24 seCoc01ub1-ine A tablet granulation is prepared from these ingredients by admixing the 2.1,22-dihydro 10 hydroxy-23,24-seco brucidine with a starch paste comprising the corn starch, milk sugar, sodium benzoate, ethyl cellulose and acacia powder in a sufficient amount of water to provide a pasty consistency. The mixture is worked until it granulates and then passed through a large mesh screen (e.g., No. 16). The granules are dried and then put through a No. 20

Following the procedure of Example 4, but substituting colubrine for brucine there is obtained a mixture of 10;- hydroxy-23,24-secocolubridine and 21,22 dihydro-lO-hydroxy-23,24-secocolubrine which may be separated by chromatography on silica gel and eluting with the appropriate solvents.

EXAMPLE 6 screen and mixed with the previously sieved talc and magnesium stearate. The resulting granulation is then gs gz fig gi pressed into tablets, each containing the specified amount of active ingredient. Following the procedure of Example 4 but substituting Similarly, all the other compounds within the purview colubrine for brucidine there is obtained a mixture of of this invention may be tableted.

TABLE I.NUCLEAR MAGNETIC RESONANCE DATA Acetate Compound C1-C4 C22 C22 0 m Methoxyls C23 1 C2 8 methyl Brucine (1); 6.78 (s) (1) 5.84 (t) (1) 3.85 (s); 3.82 (s) Brucidinen 6.58 (s) (1); 6.03 (s) (1) 5.70 (t) (1) 3.79 (s); 3.76 (s) IO-hydroxy- 0- 6.78 (s) (1); 5.71 (s) (1) 5.52 (q) (0.75) 4.92 (m) (1) 3.77 (s); 3.23 (s) 1.69(d) 0.91 (t) (0.7)

brucidine. (Example 1 21, 22-Dihydro23,24- 6.57 (s) (1); 6.09 (s) (1) 3.81 (s);3.75 (s) 0.91 (t) (3) secobrucidine (Example 4). 23,(4 secolm2r)cidine 6.60 (s) (1); 6.08 (s) (1) 5.42 (q) (1) 3.78 (s); 3.73 (s) 1.69 (d) (3) xamp e 23, 24-Seoobrucidine 6.61 (s) (I); 6.09 (s) (1) 5.32 (q) (1) 5.12 (m) (1) 3.82 (s); 3.76 (s) 1.47 (d) (3) 1.93 (s) (3) acetate (Example 3).

l Determined for deuterlochloroform solutions on a Varian A- Spec- 2 When A is present. trometer, with tetramethylsilane as internal standard. Data are pre- When A is saturated. sented as units, s-singlets, d-doublet, t-triplet, q-quartet, m-multiplet. 4 Estimated to contain about 25 percent of 10-hydroxy-21,22-dihydro- Centers of gravity were estimated visually for all signals except the 23,24-secobrucidine. aromatic multiplets. Figures in parenthesis give estimates of the proton 5 Determined on a benzene solvate. contents of the corresponding signals estimated by assuming the right aromatic proton content.

23,24 secocolubndme and 21,22-d1hydro-23,24-secocolu- S milarly, by substituting another metal from Group I bridine which may be separated by chromatography on or II of the Periodic Table for sodium in Examples 1 silica gel and eluting with the appropriate solvents. through 8, the initial compounds may be similarly reduced.

The invention may be variously otherwise embodied within the scope of the appended claims.

What is claimed is:

1. A compound selected from the group consisting of those having the formula:

CHsO

wherein W is selected from the group consisting of a double-bond and a saturated linkage hetween C-21 and C-22; R is selected from the group consisting of hydrogen and hydroxy; and R is selected from the group consisting of hydrogen and acetyl with the proviso that R is acetyl only when R is hydrogen.

3. A compound according to claim 1 that is IO-hydroxy- 23,24-secobrucidine.

4. A compound according to claim 1 that is 23,24-secobrucidine.

5. A compound according to claim 1 that is 23,24-secobrucidine acetate.

6. A compound according to claim 1 that is 21,22- dihydro-23,24-secobrucidine.

7. A compound according to claim 1 that is IO-hydroxy- 21,22-dihydro-Z3,24-secobrucidine.

References Cited UNITED STATES PATENTS 2,224,368 12/1940 Musselman 260-236 X 2,390,281 12/1945 Tischler 260-236 2,258,113 8/1956 Zellner 260236 2,858,314 10/1958 Georgian 26()287 QTHER REFERENCES Merck Index, 7th edition, pp. 172-3, 9867 relied on (1960).

Manske: The Alkaloids, vol. I, Academic Press, p. 411 relied on (1950).

Manske: The Alkaloids, vol. II (supplement to vols. I and II), Academic Press, p. 188 relied on (1960).

D. A. DAUS, Primary Examiner US. Cl. X.R. 

